Luminex® and Its Applications for Solid Organ Transplantation, Hematopoietic Stem Cell Transplantation, and Transfusion^*

Abstract

The detection of antibodies against the human leukocyte antigen (HLA) complex has become indispensable in every clinical practice. The development of solid-phase assays like the Luminex allows the standardized measurement of anti-HLA antibodies (HLAab) with high sensitivity, albeit the relevance for some clinical settings remains a matter of debate. In this review we aim to describe the principle of Luminex-based antibody detection, including two modifications that allow identifying solely complement-activating antibodies. We then describe three applications for Luminex: i) detection of HLAab preceding solid-organ transplantation and monitoring of donor-specific antibodies posttransplant as a risk factor for antibody-mediated rejection; ii) presence of HLAab in recipients as a risk for graft failure in hematopoietic stem cell transplantation, especially in haploidentical or mismatched transplantations; iii) role of HLAab in blood transfusion including refractory thrombocytopenia and selection of suitable platelet donors, transfusion-related lung injury after plasma transfusion, and immunization against HLA after red blood cell transfusion despite leukodepletion. Although the Luminex platform constitutes a potent technology for HLA antibody detection, some drawbacks require the well-educated analysis and interpretation of data in critical cases. In addition, Luminex has become an important tool to identify clinically relevant antibodies.

Interpreting Anti-HLA Antibody Testing Data

“…Phenotypic or multi-antigen beads contain Class I and Class II antigens from a single cell line, while each SAB contains a single HLA antigen(8). In both cases, the beads contain a unique ratio of different fluorochromes that provide a distinctive signal that is recognized by Luminex® technology(8). The patient's serum is incubated with the solid phase platform (beads) and a fluorescent-conjugated anti-human IgG, which binds to alloantibody bound to its antigenic target.…”

Early donor-specific antibodies in lung transplantation: Risk factors and impact on survival

“…25,26 A threshold of 1,000 mean fluorescence intensity (MFI) was used to define anti-HLA antibody positivity. The highest MFI value was considered in patients who showed DSA against more than one antigen.…”

Untitled

“…18,19 Conversely, new methodologies such as the Luminex platform have demonstrated both a greater sensitivity and an unambiguous recognition of antibodies against one or both classes. 20 The use of bead-based Luminex screening in laboratories has become widespread worldwide and has improved the detection of anti-HLA antibodies. In this context, to improve our understanding of the limitations but also of the potential of Luminex-based technology, we focused our study on interpretative and technical aspects regarding its use.…”